Hi everybody.
I´m new to this place. Me and my brother is building a tiki bar and i joined for tips and inspiration for the project.
Now for the question. I have some experience in working with wood. BUT never with bamboo. I need to split a bamboo pole about 5-6 cm thick and 2.4 meters long.
What is the best and safest way to do this? I need both of the halves to be straight. Does bamboo crack straight if i was to hammer a knife in one end and keep pounding it all the way through? The bamboo poles themselves are quite straight.

I have limited experience with Bamboo ranging from 1/2 inches dia. to nearly 5 inches in dia. They have sections that when trying to force the peices apart, stop the splitting and either break, or the split contines, but to a narrower side (weakest) So, I ended up using a tablesaw which works very well. Smooth and even cuts as long as you want them. With a sharp blade, I have ripped 18 foot long lengths without issue.

Table saw worked like a charm for me. Plus if you just want to make a notch instead of going through both sides(for corners, etc) the table saw makes that very easy too. We used a reciprocating saw to cut the pieces to length.
A helper is a bonus for that job

In the course of an ongoing tikification of a home recording studio, I came up with an economical way of splitting bamboo without spending a fortune on shipping all the way across the country.
Six-foot bamboo poles (approx 1 1/2" to 2") can be easily & affordably found at hobby supply shops (i.e., Michael's, Hobby Lobby, etc.) for $1.50 to $2.50 each. The ones I found were already burned & polished.
I cut a one inch groove into a 2x4 with a circular saw set at a 45 degree angle.
Without investing in a table saw, I cut the poles in equal enough halves to do the job. Even poles that aren't perfectly straight can be adjusted as you move the saw along the v-shaped groove. IMPORTANT: safety goggles are a must, as I found that bamboo dust gets in your eyes moreso than regular sawdust.
Depending on what kind of blade you use, you may encounter minor fraying--this can be remedied with scissors. When cross-cutting to length, however, you want to tape next to the line to be cut to reduce this.
Though not a perfectly straight cut, a circular saw does well enough to conceal any deficiencies that might not work in a more brightly-lit environment. I trimmed out a 12' x 10' installation with less than $100 in bamboo. More money to send in the direction of tiki carvers, and less into the pockets of UPS & FedEx.